Humans (人間, Ningen?), falling under the category of Primates (霊長, Reichou?), are the most prevalent species on the planet. The term is referring to mankind's current evolutionary stage as a species rather than mankind as a group. The collective will of humanity is represented by Alaya, and it is at odds with the natural forces of the planet. During the Age of Gods, humanity was much closer to the root and the gods, but that connection has dwindled over the millennia. The world was very antagonistic towards humans, so much that even someone like Gilgamesh was unable to needlessly kill people. Being closer to the origin made the power of Alaya more concentrated, and it increased the weight of each human soul in comparison to modern humans. Humanity has the potential to develop to the point where it can outlive the planet itself, such as the Liners and A-Rays.
Humans can be born with innate abilities such as extrasensory perception and other abnormal powers called ESP (超能力, Chounouryoku?). They are normally functions that aren't involved in the operation of the organisms called humans, which are the circuits that cause "supernatural phenomena" to occur. Compared to thaumaturgy, which can be trained over time, inherent ability is absolutely necessary to use ESP. Those who have these abnormal lines can cause supernatural phenomenon to happen as if they were simply breathing. Those experiencing it find it to be normal, so they only realize the abnormality of themselves for the first time when the common sense of others point this out to them.
It is possible for humans to have offspring with supernatural species, resulting in the birth of Mixed-Bloods (混血, Konketsu?). Such hybrids include offspring between humans and members of the Oni Kind, such as the Tohno and Kishima clans in Japan. While others include the half incubus Merlin, the descendant of a half succubus Natalia Kaminski and Altrouge Brunestud, the offspring between a Dead Apostle and a True Ancestor. There are even offsprings with Dragons, who are considered the strongest of the Phantasmal Species, such as Elizabeth Bathory. Such beings are seen as a distortion that needs to be exterminated in Japan, but they make for troublesome targets for the Demon Hunters. They are immune to the Edict of Binding of Houjutsu, and it is impossible to match their supernatural powers with just a human body.
Though humans are bound to the planet, Gilgamesh, thousands of years before the modern age, foresaw a future where they eventually leave the planet and reach the stars. There are also other possibilities like Notes and Tsuki no Sango.
The world of Notes, a possible future in which the planet dies and humanity continues to survive, greatly changes humanity. Regular humans without any special modifications, called "Last-Seeds", are a great minority, and said to be on the verge of extinction. The Grain in the air makes it impossible for them to live without the support of medicine or machines to breathe properly. They also cannot eat food developed in factories due to the nutritional value being high enough to act poisonous to them. Due to these factors, other races feel they have no value. After the destruction of the Western Continent, Gun God is believed to be the last surviving unmodified human.
There are two main divisions of the humans who did evolve to adapt to the environment of the ruined world, Liners (人間種, Ningenshu?, mankind) and A-Rays (亜麗百種, Areihyakushu?, one hundred subspecies). Liners are simply humans with the ability to live in an environment that is abundant with Grain. A-Rays, on the other hand, are beings that were artificially created before the death of the world. They have since been modified and enhanced to survive in the barren world. They survive by absorbing Grain from the atmosphere into their bodies, allowing them to have power far beyond the Liners. Called the "One hundred subspecies", there exists a total of one hundred different species, though Liners are technically included, and those numbered one to ten actually only have one member each. Though some have humanoid bodies, the majority are a mixture between primates and other lifeforms. They went to war with the humans after the death of the planet in order to take it as their own, which led to the development of Liners in order for humanity to survive. The arrival of the Aristoteles led to a cease fire after a number of humans and subspecies were wiped out. Liners currently work to rebuild their damaged population while working with the A-Rays to combat their mutual enemy.
Though Liners are mostly inferior to the A-Rays, the development of Ether Liners (騎士, Kishi?, knights) balanced out their combative forces. The "Knights" are Liners that were strongly affected by the abnormal environment of the dead planet, having Grain crystallize in their bodies as if it were bone. After reaching maturity, the Grain is released into a definite form outside their bodies. These masses of Grain become known as Knight Arms (魔剣, Maken?, Demonic Swords), which have a variety of effects and allow them to fight against A-Rays without any support.  The number of people who obtain a true Demonic Sword, one powerful enough to be called a weapon, is small, and their numbers only total seventy-eight.
Tsuki no SangoEdit
The humanity of Tsuki no Sango can be called dead in a sense. They have stagnated after having lost their drive to expand, invent, and propagate, as if the entire species declared “Everything is far too troublesome.” Only one tenth of the population have the drive to "keep trying", so that is enough to keep the failing race alive. Before its stagnation, they attempted the Lunar Immigration Plan to the Moon to overcome their overpopulation crisis, creating a lunar city upon the new frontier. During this expansion, there was an unexpected event, a pole shift on Earth and the sudden lose of humanity's fire, that marked the end of the race. They, not needing civilization to live on Earth, pushed all hope onto those living on the Moon, where civilization was a necessity, after having grown tired of it.
The Moon and Earth became completely independent in only fifty years, sealing their doors after deciding there was nothing to negotiate. Those on Earth made do even with their slowly dwindling population, while those on the Moon secured their living conditions within their environment. The Gregorian calendar was lost, and the conditions on Earth worsened, with the oxygen thinning over time. The people still trying to survive, the Committee for Restoring Humanity, created cities, a lost concept for those in stagnation, in an attempt to return to the basics of life with love as their fundamental principle. While it was possible for the people on Earth to reach the Moon, it became impossible to leave, so it was a one-way trip.
Those on the Moon disappeared after a time, and the Girl of the Moon, created to conform to man’s image of beauty, felt that they all must have "gone to sleep" at once because "staying awake" had become too troublesome, or, due to their rule forbidding residents loving each other, had all been exiled to Earth in punishment. Those who fell in love with someone from Earth were separated forever as punishment. They were so much more advanced than Earth, but were never able to overcome the emotional deficiencies and self-destructed. After the fall of the Girl of the Moon, the coral created began to produce great quantities of oxygen and nitrogen, allowing for humanity to live for a little longer.
 Kara no Kyoukai Special Pamphlet - Encyclopedia: Psychic Power [Others] English | Japanese
Psychic Power [Others]
Abnormal powers. Functions that normal humans do not possess. A kind of circuitry that leads to what are commonly called paranormal activities.
Different from magecraft, inborn talents are absolutely necessary for ESP. Those possessing ESP circuits can induce paranormal phenomenons as naturally as breathing. The ESPers themselves take ESP for granted, and treat it as something they simply "can do". They only realise that they are abnormal after others (who can only comprehend "normal") have pointed it out.
In this story, Asagami Fujino is an ESPer, but since she was tampered with somewhat, her ability falls between ESP and magecraft.
ESP is normally an incidental occurrence, a sudden mutation limited to one generation.
 Melty Blood Act Cadenza PS2 Manual - Dictionary: Mixed-Bloods [Term], p.056 English | Japanese
Refers to the descendants of humans who consorted with something "inhuman" in the distant past. Tohno Akiha and Kishima Kouma fall under this classification.
Though their blood is growing thinner with each successive generation, on rare occasions a child is born who has strongly inherited that "inhuman" characteristic.
As for Tohno Akiha, her blood is primarily human, but what inhuman blood she does have is exceptionally high class. Because of this, she could be considered the answer to the demon hybrids' evolution, capable of awakening as a demon hybrid while still remaining a human being.
Kouma, on the other hand, is an archetypical demon hybrid whose oni blood runs too thick, making life as a human completely impossible.
Notes - Humans [Last-Seed]
Human species who hasn't received any modification, or their descendent. Since they are no longer able to survive on this planet, it is said that they are on the verge of extinction.
In order for humans to live outside, they need support from medication or machines. They can't directly inhale the air, nor can they eat the food made in the factory because they raise the physical ability too much that they become poisonous.
They are rare, but have no value.
Notes - Human Species [liner]
Human race on the Land of Steel. Evolved form of the old human beings who adapted to this world without changing their shape. They technically belong to the A-rays as well.
They were able to adapt and live on today's environment, but they still don't carry any ability more than a normal human being.
They are building a country in order to reconstruct their old civilization. Cease-fire with the Hundred A-rays.
Notes - Hundred Subspecies [a-ray]
Next generation primates that were created by the human species who used up all the planet's resource.
They were modeled after the living things that used to exist on the planet. They were modified/enhanced in order for them to survive on the corrupted planet. There were numerous branches to the A-rays, and they were categorized into about 100 major species. From 1 to 10 consists of only one type of A-rays each and not a mass.
Some carry the genes of humans and they look like us, but a large part of them are mix/evolved form of various creatures and primates.
Notes - Demonic Sword [knight arms]
The name of the weapon that Knights carry.
All human species born in this world are effected by Gin. Babies born with a large amount of Gin in them shape it as if it's their bones during their lives, and when they reach adulthood, it is laid outside their body. Because it is created with the unanalyzed entity Gin, it is able to cause various effects and its power is strong enough to be considered a weapon.
Only few humans can shape the Demonic Swords, and those who carry a Demonic Sword powerful enough to be used for war are considered as Knights. Only one Demonic Sword exists per Knight.
Notes - Knights [Ether Liner]
Life form that received an even stronger effect from the drastic environment. They wield a special weapon called the Demonic Swords. Aggressive species that can fight the A-rays equally without any support of firearms of the old age. There are currently 78 Knights enlisted.
|Ado Edem • Aristoteles • (Type Mercury • Type Venus • Type Moon) • Gun God • Humans • Land of Steel|
|Bounded Field • Conceptual Weapon • Gradation Air • Magic • (Second Magic • Third Magic) • Magical Spells • Marble Phantasm • Mystic Code (Azoth Sword) • Mystic Eyes • Mystic Eyes of Death Perception • Psychic • Reality Marble|
|Demons • Divine Spirit • Dragon • Familiar • Homunculus • Humans • Phantasmal Species • Spirits • Vampire|
|Holy Grail War|
|Command Spells • Great Grail • Heroic Spirit • Holy Grail • Master • Noble Phantasm • Servant • Servant classes • Servant Parameters|
|Barthomeloi Lorelei • Magician • Magus • Sealing Designation|
|Akasha • Chants and Incantations • Elements • World • Magic Circuit • Prana • Soul • Magic Crest|